Cyan couplers for color photography



United States Patent 3 458,315 CYAN COUPLERS FOR COLOR PHOTOGRAPHYAnthony Loria, Rochester, N.Y., assignor to Eastman Kodak Company,Rochester, N.Y., a corporation of New Jersey No Drawing. Filed Oct. 24,1965, Ser. No. 504,994 Int. Cl. G03c 1/40 11.5. Cl. 9656.2 12 ClaimsABSTRACT OF THE DISCLOSURE This invention relates to color photographyand more particularly to new and improved cyan-dye-forming couplercompounds for use in image-forming systems, and to processes utilizingsuch couplers for the formation of images. In a more specific aspect, myinvention relates to two-equivalent coupler compounds for forming cyandye images in color photography.

The formation of color photographic images by the image-wise coupling ofoxidized aromatic primary amino developing agents with color-forming orcoupling compounds to form indoaniline, indophenol, and azomethine dyesis well known. In these processes, the subtractive process of colorformation is ordinarily used and the image dyes customarily formed arecyan, magenta, and yellow, the colors that are complementary to theprimary colors, red, green, and blue, respectively. Usually phenol ornaphthol couplers are used to form the cyan dye image; pyrazolone orcyanoacetyl derivative couplers are used to form the magenta dye image;and acylacetamide couplers are used to form the yellow dye image.

In these color photographic systems, the color-forming coupler may beeither in the developer solution or incorporated in the light-sensitivephotographic emulsion layer so that, during development, it is availablein the emulsion layer to react with the color developing agent that isoxidized by silver image development. Difiusible couplers are used incolor developer solutions. Nondiffusing couplers are incorporated inphotographic emulsion layers. When the dye image formed is to be used insitu, couplers are selected which form nondiffusing dyes. For imagetransfer color processes, couplers are used which will producedilfusible dyes capable of being mordanted or fixed in the receivingsheet.

Most of the couplers which have been used in the various colorphotographic systems described above are four-equivalent couplers, thatis, they require reduction of 4 moles of silver halide for the formationof 1 mole of dye. Certain of the prior-art couplers are two-equivalentcouplers, i.e., they require reduction of only 2 moles of silver halidefor the formation of 1 mole of dye. However, some of the prior-artcouplers exhibit serious disadvantages such as low reactivity, formationof an unacceptably high level of color fog, and other undesirable sidereactions.

It is an object of my invention to provide new and improvedtwo-equivalent l-naphthol couplers capable of forming a dye on couplingwith the oxidation product of an aromatic amino developing agent, saidcouplers being characterized from prior art cyan forming couplers byhaving an imido group in the coupling position.

3,458,315 Patented July 29, 1969 It is a second object to provide suchcouplers having a materially reduced tendency to produce unwanted colordensity in the nonimage areas during color development.

It is another object of this invention to provide such two-equivalentcouplers with greatly reduced propensity to unwanted side reactionsduring color development and hence higher dye yield.

It is a further object of this invention to provide new and improvedtwo-equivalent cyan couplers which have goOd reactivity, therebyobviating prolonged or forced development.

It is another object of my invention to provide improved colorphotographic image-forming layers containing my novel couplers dispersedin a colloidal filmforming binder.

It is another object of my invention to provide a simple, economical,and reproducible process for preparing these couplers in high yield.

It is a further object to provide photographic silver halide-gelatinemulsion layers containing these new couplers for use in colorphotography.

It is another object of my invention to provide improved photog'raphiccyan dye images by the use of these couplers.

These and other objects will appear from the following description of myinvention. These and other objects are accomplished according to myinvention by the preparation and use of my two-equivalent l-naphtholcouplers, in which the 4-position, that is, the coupling position issubstituted with an imido group, preferably a 2,5-diketopolyhydropyrrolegroup having from two to four hydrogen atoms, said group being attachedto the 4-position of the naphthol ring through the nitrogen atom in thepyrrole ring. The said imido group can be either monofunctional havingone coupler moiety attached to it as described, or bifunctional with thenitrogen of each imido function attached to the carbon atom in thecoupling position of separate coupler moieties. My couplers are derivedfrom any of the known four-equivalent l-naphthol couplers.

Included among the outstanding 4-imido-substituted couplers according tomy invention are 4-cyclic imido derivatives of l-hydroxy-Z-naphthamidesof the general formula:

in which R and R represent any combination of hydro gen, an alkylradical having either a straight or a branched chain of from 1 to 30carbon atoms, a monoor bicyclic alkyl radical such as cyclohexyl,ter-penyl, e.g., a norbornyl radical, etc., an aryl radical (e.g.,phenyl, t-olyl, naphthyl, etc.), a heterocyclic radical having from 5 to6 members in the heterocyclic ring (e.g., benzimidazolyl, benzoxazolyl,benzoselenazolyl, benzothiazolyl, thiazolyl, pyridyl, quinolyl, etc.),or together R and R provide the non-metallic atoms necessary to completewith the nitrogen atom between them, a heterocyclic group having 5 to 6members in the ring, e.g., morpholine, piperidine, pyridine, pyrrolyl,etc. These groups, that is, alkyl, aryl, and heterocyclic as definedabove may contain substituent groups such as halogen (e.g., chlorine,bromine, etc.), cyano, hydroxyl, carboxyl, amino, substituted amino(e.g., alkylamino, dialkylamino, anilino, N-alkylanilino, etc.), acarboxyl ester (e.g., a carboalkoxy, a carboaryloxy, etc.), an amido(e.g., acetamido, butyramido, ethylsulfonamido, N-methyl-benzamido, N-propylbenzamido, 4-t-butylbenzamido, etc.), a carbamyl (e.g., carbamyl,N-octadecylcarbarnyl, N,N-dihexylcarbamyl, N-methyl-N-phenylcarbamyl,3-pentadecylphenylcarbamyl, etc.), a sulfamyl (e.g., sulfamyl,N-propylsulfamyl, N-tolylsulfamyl, etc.), an alkoxy (e.g., ethoxy,octadecoxy, etc.), an aryloxy (e.g. phenoxy, tolyloxy, naphthyloxy,etc.), sulfo, sulfonyl, a substituted sulfonyl (e.g., methylsulfonyl,octadecylsulfonyl, ethoxysulfonyl, decoxysulfonyl, phenylsulfonyl,tolylsulfonyl, phenoxy sulfonyl, etc.), and in which R R R and R mayrepresent any combination of hydrogen, halogen (e.g., chlorine, bromine,etc.), alkyl having from 1 to 30 carbon atoms, alkoxy having from 1 to30 carbon atoms, aryl, and aryloxy groups which may be unsubstituted orsubstituted by any of the groups described as substituents for the R andR groups, and R and R together may comprise a valence bond between thetwo carbon atoms to which they are attached and R R R and R may togethercomprise the atoms necessary to complete an isocyclic or heterocyclicring, saturated or unsaturated, such, for example, as benzene, pyridine,cyclohexane, cyclohexene, furane, bicycloheptane, bicycloheptene, etc.The R-; group represents hydrogen, lower alkyl having from 1 to 4 carbonatoms, lower alkoxy having from 1 to 4 carbon atoms, an amido grouphaving from 1 to 4 carbon atoms, etc.

My novel couplers are characterized by an imido substituent in thecoupling position, have good coupling reactivity and other valuableproperties. Thus they induce unusually low levels of unwanted color fogupon color development, and they show good stability. Good couplingreactivity is obtained with couplers of my invention when incorporatedin emulsion layers without the use of high-boiling coupler solvents.When high-boiling solvents are used to disperse these couplers, high dyeyield and low color fog are attained over a wide range ofcoupler-to-solvent ratios. When the diifusible couplers of my inventionare used in color developing solution, good reactivity and dye yield areachieved.

Included among my novel couplers are the following typical exampleswhich are used to illustrate but not limit my invention:

( l l-hydroxy-4-ma1eimido-2-naphthamide CONH:

CH=(|JN (2) 1-hydroxy-4-(octadecylsuccinimido)-N-ethyl-3,5'-dicarboxy-Z-naphthanilide (EH C O OH (32 CON COOH (3)1-hydroxy-4-succinimido-N-[6-(4-t-butylphenoxy)- butyl]-2-naphthamide(4) l-l1ydroXy-4-maleimido-N-ethyl-2-naphthamide (5 1-hydroxy-4-(cis-4-cyclohexenyl-l,Z-dicarboximido -2'-methoxy-2-naphthanilide CONHto (6) l-hydroxy-4- l ,2-cyclohexyldicarboximido -N- (B-phenylethyl-2-naphthamide (7) 1-hydroxy-4-succinimido-N- 3- (Z-acetamidophenylethyl]-2-naphthamide (8) l-hydroxy-4- (4-carb oxyphthalimido -N-{[3-{4-[oc- (2,4-di-t-amylphenoxy)vacetamido] phenyl}ethyl}-2- naphthamide (9)l-hydroxy-4-(4-methyl-4-cyclohexenyl-1,2-dicarboximido-N,N-dioctyl-2-naphthamide (l0) 1hydroxy-4-(bicycle-[2,2,1]-5-heptenyl-2,3-dicarboximido) -4'-(4-t-butylphenoxy -2-naphthanilide l l) 1-hydroxy-4-(l,2-cyclohexyldicarboximido -2'-tetradecyloxy-Z-naphthanilide 1i! 231420 o=0 x=0 (12) l-hydroxy-4-(octadecylsuccinimido)-3,5-dicarboxy-2-naphthanilide (l3) 1-hydroxy-4-(1,2-cyclohexyldicarb oximido -3 [0L (S-pentadecylphenoxy)butyramidoi]-2-naphthanilide l4) 1-hydroxy-4- octadecylsuccinimido) -N-methyl-4-sulfo-2-naphthani1ide socluim salt 15)1-hydroxy-4-phthalimido-N-octadecyl-3',5'-dicarboxy-Z-naphthanilide 16)1-hydroxy-4-maleimido-N-{B-{4- 2-2,4-di-t-amylphenoxy)-5-(3,5-disulfobenzamido)benzamido]phenyl}ethyl}-2-naphthamide disodium salt (17 l-hydroxy-4- [4-4-hydroxyphenylazo phthalimido] 4'- (4-t-butylphenoxy) -2-naphthanilidel 8 l-hydroXy-4-(cis-4-cyclohexenyl-1,2-dicarboximido-N-octadecyl-Z-naphthamide (l9)lhydroXy-4-succinimido-Z-naphthomorpholide (20)l-hydroxy-4-(4-methyl-4-cyclohexenyl-1,Z-dicarboximido -N-cycl ohexyl-2-n aphthamide (21 l-hydroxy-4-succinimido-N-methyl-N-(B-sulfoethyl)-2-naphthamide sodium salt (22) 1-hydroXy-4-phtha1imido-N-[B- (Z-acetamidophenyl ethyl] -2-naphthamide (23)1-hydroxy-4-(1,Z-cyclohexyldicarboximido)N-methyl-4'-sulfo-2-naphthanilide sodium salt (24) l-hydroxy-4-dodecenylsuccinimido -N-ethyl-3 ',5

dicarboxy-2-naphthanilide (25) 1-hydroxy-4-phthalimido-N-ethyl-3',5-disulfo-2- naphthanilide disodium salt (26) 1-hydroxy-4- 4-carboxyphthalimido -N- (Z-benzimid azolyl -2-naphthamide (27)1-hydroxy-4-phthalimido-N-methyl-N- ,G-sulfoethyl)-2-naphthamide sodiumsalt (28) 1-hydroxy-4-maleimido-N,N- (dic arboxymethyl -2- naphthamide(29) l-hydroxy-4-phthalimido-2-naphth amide (3l-hydroxy-4-phthalimido-N- [8- 2,4-di-t-amylphenoxy -butyl]-2-naphthamide (31) 1-hydroxy-4-(dodecenylsuccinimido -N-[6-(2,4-dit-amylphenoxy butyl -2-naphthamide (3 2) 1-hydroxy-4-(1,2-cyclohexyldicarb oximido -N- (2,4-di-t-amylphenoxy) butyl] -2-naphth amide (33)l-hydroxy-4-(bicyclo-[2,2,1]-5-heptenyl-2,3-dicarboximido N [5-2,4-di-t-amylphenoxy butyl] -2- naphthamide (34)l-hydroxy-4-maleimido-N- [5- (2,4-di-t-amylphenoxy -butyl -2-naphthamide(3 S) l-hydroxy-4- (4-methyl-4-cyclohexenyl-1 ,Z-dicarboximido -N- [62,4-di-t-amylphen0xy butyl] -2- naphthamide (3 6)1-hydroxy-4-succinimido-N- [6- 2,4-di-t-amylphenoxy butyl]-2-naphthamide (3 7) 1-hydroxy-4-(cis-4-cyclohexenyl-1,2-dicarboximido-N- [5- 2,4-di-t-arnylphenoxy butyl 1 -2-naphthamide (3 8) 1-hydroxy-4-4-carb oxyphthalimido -N' [6- 2,4-di-- t-amylphenoxy butyl]-2-naphthamide (3 9) l-hydroxy-4- 2,3-furyldicarboximido -2-naphthamideCONH:

(40) 1-hydroxy-4[3-(1,2-dicarboxyethyl)succinimido]-N-ethyl-Z-naphthamide OH 6 I V@ C ONHCzHs The following coupler willserve to illustrate my couplers that are derived from a prior artfour-equivalent coupler and contains a bifunctional imido group.

3,3 bis[1 (3-ethylcarbamyl-4-hydroxynaphthyl)suc- Although this couplercontains two identical coupler moieties, the two coupler moieties can bedilferent if this is desired.

Among still further couplers that are used to advantage according to myinvention are included the following:

1-hydroxy-4- octadecylsuccinimido) -N-ethyl-3 ',5-acetoxy-2-naphthanilide,

1-hydroxy-4-(octadecylsuccinimido)-N-ethyl2',4',6'-trichloro-Z-naphthanilide,

1-hydroxy-4- octadecylsuccinimido -N-ethyl-3 '-cyano- Z-naphthanilide,

1-hydroxy-4-succinimido-N- [fl- Z-dimethylaminophenyl) ethyl]-2-naphthamide,

1-hydroxy-4-succinimido-N-methyl-N- (,B-sulfamylethyl) Z-naphthamide,

1-hydroxy-4- octadecylsuccinimido-N-methyl-4'-methylsulfamyl-Z-naphthanilide,

1-hydroxy-4-succinimido-J-methyl-N- (,B-ethylcarbamyl ethyl)-2-naphthamide,

1-hydroxy-4- (methoxsuccinimido -N-ethyl-3',5-dicarboxy-2-naphthanilide,

1-hydroxvy-4- (phenylsuccinimido -N-ethyl-3,5'dicarboxy-2-naphthanilide,

1-hydoxy-4- (chlorosuccinimido -N-ethyl-3 ,5 -dicarboxy-Z-naphthanilide, etc.

In the couplers of my invention, which are distinguished by their highcoupling reactivity and the reduced tendency to produce color fog duringcolor development, the imido groups provide a means of attaching othersubstituents such as, for example, preformed dyes useful in colorcorrection, dye transfer processes, and the like. Additional ballastinggroups can be introduced conveniently in the imido groups; theseballasting groups are then eliminated during the coupling reaction withoxidized color developer which forms the image dyes.

The diffusible couplers of my invention, such as couplers 1, 4, 5, 6, 7,19, 20, 21, 22, 23, 25, 26, 27, 28, 29, and 39, are employedadvantageously in color developlng solutions used to color developlight-sensitive color photographic elements which do not contain thecolorforming coupler. Any of the well known primary aromatic aminocolor-forming silver-halide developing agents such as thephenylenediamines, e.g., diethyl-p-phenylenediamine hydrochloride,monomethyl-p-phenylenediamine hydrochloride, dimethyl-p-phenylenediaminehydrochloride, 2-amino-5-diethylaminotoluene hydrochloride,2-amino-5(N-ethyl-N-laurylamino)toluene,

N-ethyl-N- (p-methanesulfoamidoethyl -3-methyl-4-ami noaniline, 4-[N-ethyl-N-(/B-hydroxyethyl) amino] aniline, etc., the p-aminophenolsand their substitution products in which the amino group isunsubstituted, are used in the alkaline developing solution with mycouplers. Various other materials may be included in the developersolutions depending upon the particular requirements, for example, analkali metal sulfite, carbonate, bisulfite, bromide, iodide, etc., andthe thickening agents used in viscous developer compositions such ascarboxymethylcellulose, carboxyethyl cellulose, gelatin, etc. Thefollowing is a typical developer solution given to illustrate but notlimit my invention.

G. 2-amino-5-diethylarninotoluene HCl 2.0 Sodium sulfite (anhydrous) 2.0Sodium carbonate monohydrate 20.0 Potassium bromide 1.0

Coupler 2.0

Water to 1000.0 ml.

Couplers 21, 23, 25, 27, and 28 are diffusible couplers which formdilfusible dyes on coupling with oxidized color developer, and are usedto advantage in photographic emulsion layers.

The other coupler examples used to illustrate my invention arenondiffusing and are used to advantage in photographic emulsion layers.Couplers, such as 2, 8, 12, 14, 15, 16, 24, and 38, illustrate thosethat are incorporated as Fischer-type couplers. The other nondiffusingcouplers, e.g., 9, 10, ll, 13, 18, 30, 31, 32, 33, 34, 35, 36, and 37,are incorporated in emulsion layers by methods such as are described byMannes et al., US. Patent 2,304,939, issued December 15, 1942, Jelley etal., U.S. Patent 3,322,- 027, issued June 15, 1943, etc., in whichhigh-boiling organic solvents are used to dissolve the coupler, and bymethods described in Vittum et al., US. Patent 2,801,- 170 and Fierke etal., U.S. Patent 2,801,171, both issued July 30, 1957, and Julian, US.Patent 2,949,360, issued Aug. 16, 1960, in which low-boiling orwater-soluble organic solvents are used with or in place of thehighboiling solvent. The use of such coupler dispersions permits thinneremulsion layers. These thinner layers are very desirable because theycause less light scattering, consequently, they produce sharper images.

The nondiffusing couplers 2, 12, 14, and 24 contain free acid groups(i.e., carboxy and sulfo) so that the dyes formed by these couplers arerendered ditfusible. This valuable property enables these couplers to beused to advantage in image-transfer processes and as incorporated,diffusible-dye-forming competing couplers in conventional color films.

Coupler 17 contains a preformed dye attached to the coupler moietythrough the imido group. This dye is eliminated during the coupling ofthe coupler with an oxidized color developer and diffuses out of thefilm. This coupler is used to advantage as a yellow-colored coupler forthe purpose of correcting for the unwanted blue absorption of the cyanimage dyes, i.e., that formed from the coupler itself as well as thatformed from other cyan couplers. Generally, such a coupler as this wouldbe used in combination with another image-forming cyan coupler in thesame layer.

My couplers are used to advantage in the color development ofphotographic hydrophilic colloid-silver halide emulsion layers of thedeveloping-out type in the emulsion layer or a contiguous layer. Theemulsions may contain silver chloride, silver bromide, silver iodide,silver chlorobromide, silver bromoiodide, silver chlorobromoiodide,etc., as the light-sensitive material.

Any of the hydrophilic colloids used in making photographic emulsionscan be used to advantage including gelatin, colloidal albumin, acellulose derivative, or a synthetic resin, for instance, a polyvinylcompound, etc.

The emulsions used in the photographic element of my invention can bechemically or optically sensitized by methods well known in the art.

The couplers of my invention are also used to advantage in image-forminglayers, either alone or with imageforming compounds other than silverhalide, such as ZnO, ZnS, CdS, CdSe, NiS, etc., either with or withoutbinders such as gelatin, polyvinyl alcohol, etc.

Usually my emulsions are coated on photographic supports in the form ofmultilayer color photographic elements wherein at least threedifierently sensitized emulsion layers are coated over one another onthe support. Usually the support is coated in succession with aredsensitive layer, a green-sensitive layer, and a blue-sensitive layereither with or without a Carey Lea silver yellow filter layer betweenthe blue-sensitive and greensensitive layers. The three differentlycolor sensitized layers may be arranged in any other order over oneanother that is desirable; however, the Carey Lea filter layer obviouslywould not be put over the blue-sensitive layer. Preferably, theselight-sensitive layers are arranged on the same side of the support.

Elements made for image transfer processing may use a separate receptionsheet which is contacted with the light-sensitive layer during itsdevelopment or the reception layer may be an integral part of thelight-sensitive element. Any of the support materials mentioned previously may be used as the support for a separate reception sheet. Thereception layer comprises a hydrophilic colloid layer containing acationic mordant, e.g., the polymers of amino guanidine derivatives ofvinyl methyl ketone such as described in Minsk US. Patent 2,882,156,granted Apr. 14, 1959.

My invention is further illustrated by the following typical examples.

Example 1 Samples of a single layer gelatin silver bromoiodide coatingwere exposed (i.e., for second on a 1B intensity scale sensitometer).These strips were then processed to color positives by the followingprocess; all process temperatures were 68".

A conventional MQ Developer comprising an alkaline solution ofhydroquinone and 4-methy1aminopl1enol sulfate was used. The bleach wasconventional, comprising aqueous alkali metal ferricyanide.

The Color Developer had the formula:

Benzyl alcohol ml 4.0 Sodium hexametaphosphate g 0.5 Sodium sulfite,desiccated g 2.0 Sodium hydroxide g 0.16 Coupler 1 g 2.0 4-amino-3-methyl-N-ethyl-N-[p (methanesulfonamido)ethyl]anilinesesquisulfate hydrate g.. 5.0 Sodium carbonate monohydrate g 50.0 Sodiumbromide g 0.2 Water to 1 liter.

pH to 10.75.

'lhe couplers used in the above mentioned developer formula. wereCouplers 1, 4, 5, 6, 7, 19, 20, 22, 26, 29, and 39, respectively.

Good cyan dye images were formed in each of the respective strips.

Example 2 Single layer gelatin silver bromoiodide coatings were preparedcontaining Couplers 3, 9, 10 11, and 13, respectively. Each of thesecouplers were dispersed in said coatings in the form of afinely-dispersed solution of the coupler in coupler solvent,di-n-butylphthalate. These coatings contained 10 parts of gelatin, 5parts of silver, 2 parts of coupler, and 1 part of coupler solvent.Samples of the above mentioned coatings were given -second exposure on a1B intensity scale sensitometer and processed in a conventional mannerto color negatives, respectively, using the following developersolution:

Sodium sulfite (anhydrous) g 2.0 2-amino-S-diethylaminotoluene HC1 'g2.0 Sodium carbonate monohydrate g 20.0 Potassium bromide g 2.0 Water to1.0 1.

pH to 10.86.

Each of the processed strips contained high quality cyan dye imageshaving good heat and light stability and low fog.

9 Example 3 Single layer gelatin silver bromoiodide coatings containingCouplers 2, 12, 14, and 24, respectively, were prepared. These coatingswere similar to those described in Example 2 above except that thecouplers were disspersed directly in the gelatin. Samples of thesecoatings were exposed as described in Example 2 above, and processed bydeveloping each of them for minutes at 75 F. in contact with a receivingsheet containing a mordant which had been presoaked in the followingdeveloper solution:

G. Sodium carbonate monohydrate 22.0 Ascorbic acid 0.24 Potassiumbromide 0.8 Sodium sulfite (anhydrous) 2.0

4-amino N ethyl-N-(B-hydroxyethyl)-aniline sulfate 11.0 Water to make1.0 liter. pH adjusted to 12.5 using 20% sodium hydroxide solution.

After the development period, samples of the film were removed from themordant receiving sheet, in which sheets were contained the respectivetransferred and mordanted cyan dye images.

Example 4 Single layer camera speed gelatin silver bromoiodide emulsionscontaining cyan-forming coupler and coupler solvent di-n-butyl phthalatewere made for my couplers 30 to 35, respectively. The coatings containedparts of gelatin, 5 parts of silver halide, 2 parts of coupler and 1part of coupler solvent by weight.

Strips of the above coatings were given -second exposure on a 1Bintensity scale sensitometer and processed through the followingprocess:

Process step: Time Water dip 30 Development 10 Stop bath 5' Ferricyanidebeach 5' Wash 5 Fixing bath 5' Wash 10 Photo-Flo (wetting agentsolution) 30 The following developer solutions were used:

Developer 1 Sodium sulfite (anhydrous) 24-amino-N,N-diethyl-3-methylaniline hydrochloride 2 Sodium carbonatemonohydrate 20 Potassium bromide 2 Water to 1 liter.

Developer 2 Benzyl alcohol ml 4.0

Sodium sulfite (anhydrous) gm 2.0

4 amino N ethyl 3 methyl N [,8 (methylsulfonamido)ethyl] anilinesesquisulfate hydrate Sodium carbonate, monohydrate gm 50.0

Sodium bromide gm 0.86

Sodium hydroxide (20% solution) ml 4.0

Sodium hexameta phosphate gm 0.5

Water to 1.0 liter.

The resulting cyan dye images were observed with a spectrophotometer todetermine the A-max values. The

photo data are given for the above mentioned processed strips below.

Coupler No. Developer N0.

Similarly, other couplers of my invention are used to advantage in colorphotography as illustrated previously with representative couplers.Further, the couplers of my invention are valuable as cyan image-formingcouplers in multilayer photographic color films containing other classesof couplers in the other layers of said film. Such other couplers are,for example, yellow image-forming couplers containing a methylene orsubstituted methylene group having two carbonyl groups directly attachedthereto, and magenta image-forming couplers such as 5- pyrazolones,cyanoacetyl coumarones, etc.

In general, my couplers are the product of the reaction of a1-hydr0xy-4-amino-2-naphthamide with the appropriately substitutedanhydride.

The following preparation of Coupler 30 illustrates the method used toprepare the 1-hydr0xy-4-imido couplers of my invention.

A mixture of 24.5 g. of Intermediate 2 below and 7.4 g. of phthalicanhydride were heated at reflux in 400 ml. of glacial acetic acid for 6hours, after which time the solid which had separated was collected,washed on the funnel with water, and air dried. This solid wasrecrystallized from dioxane, yielding the product.

Intermediate 1: 1-hydroxy-4-(4-methoxyphenylazo)-N- [6(2,4-di-t-amylphenoxy)butyl]-2-naphthamide.-To a cold (5 C.) solution of12 g. of p-anisidine in 25 ml. of concentrated hydrochloric acid and 75ml. of water was added dropwise with stirring, a solution of 7.2 g. ofsodium nitrite in 40 ml. of water. The resulting diazonium solution wasadded dropwise at a rapid rate with stirring to a solution of 47.5 g. ofl-hydroxy-N-[5-(2,4-di-tamylphenoxy)butyl]-2-naphthamide (US. Patent2,474,- 293) in 700 ml. of pyridine at 5 C., after which time thetemperature of the mixture was permitted to come to 25 C. This mixturewas then poured with stirring into 3 liters of water. The solid whichseparated was collected and recrystallized successively from methylalcohol and acetonitrile, yielding the product.

Intermediate 2:l-hydroxy-4-amino-N-[6-(2,4-di-t-amylphenoxy)butyl]-2-naphthamide.Amixture of 12 g. of Intermediate 1 above in ml. of ethanol washydrogenated using the Parr hydrogenation apparatus at room temperaturewith Raney nickel as the catalyst. After the reduction was completed,the catalyst was removed by filtration and the filtrate was diluted with100 ml. of water, whereupon a solid crystallized, was filtered, washedwith water, and dried. It was then recrystallized from cyclohexane,yielding the product.

The bis type of couplers illustrated by 3,3'-bis[1-(3-ethylcarbamyl-4-hydroxynaphthyl)succinimide] are prepared to advantageby reacting the appropriate bifunctional anhydride (e.g.,4,4'-bis(succinic anhydride) in the immediate example) with the 4-aminoderivative of the 1- naphthol coupler (e.g.,4-amino-l-hydroxy-N-ethyl-Z- naphthamide in the immediate example).

Unsymmetrical couplers of my invention having two dilferent couplermoities per molecule are prepared to advantage by reacting theappropriate 4-(1',2'-dicarboxyethyl)succinic anhydride with the 4-aminoderivative of one l-naphthol coupler followed by appropriate treatmentof the resulting coupler to remove a molecule of water from each of the1,2-dicarboxyethyl groups to form the corresponding anhydride andsubsequently reacting this compound with the second 4-amino-1-naphtholcoupler.

Similarly, the other couplers of my invention are readily prepared bythe illustrative reactions described. The parent four-equivalentcouplers and the appropriate acid anhydrides are prepared by methodswell known in the art. Many of these compounds are available.

The two-equivalent image-forming couplers of my invention aredistinguished from other two-equivalent couplers by having an imidogroup substituted on the coupling position of the coupler molecule. Mycouplers are characterized by not producing color fog, a problem withcertain prior art two-equivalent couplers, and by having good couplingreactivity. These couplers are dispersed readily in emulsion layers as acoupler solvent solution having a wide range of coupler to solventratios.

My couplers are not only valuable for the reasons cited, but becausephotographic emulsion layers color developed with them require onlyone-half the amount of silver halide required by four-equivalentcouplers. Of particular value are certain of my nondiffusing couplerswhich have high coupling reactivity when dispersed in photographicemulsion layers without any high boiling solvent. These couplers arecoated to advantage in particularly thin layers that produce good sharpimages. The couplers of my invention may be used in emulsion layerseither alone or admixed with other couplers, and the like.

The invention has been described in detail with particular reference topreferred embodiments thereof but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention as described hereinabove and as defined in the appendedclaims.

I claim:

1. An image-forming layer containing a two-equivalent coupler which iscapable of forming a dye on coupling with the oxidation product of anaromatic amino developing agent, said coupler containing at least one4-hydroxyl-naphthyl group wherein the hydrogen atom of the 1- positionof said naphthyl group has been replaced with an imido group.

2. An image-forming layer containing a coupler of the formula:

wherein R and R each represent a group selected from the classconsisting of the hydrogen atom, an alkyl radical, an aryl radical,heterocyclic radical having to 6 members in the ring, and, together, thenonmetallic atoms necessary to complete with the nitrogen atom betweenthem a nitrogen containing heterocyclic ring having from 5 to 6 membersin the ring; R R R and R each represent a group selected from the classconsisting of the hydrogen atom, an alkyl radical, an alkoxy radical, anaryl radical, an aryloxy radical, R and R taken together form a valencebond between the two carbon atoms, and R R R and R taken togetherprovide the atoms necessary to complete a ring selected from the classconsisting of isocyclic and heterocyclic, and R represents a groupselected from the class consisting of hydrogen, lower alkyl, loweralkoxy, and a lower amido group.

3. An image-forming layer of claim 2 silver halide emulsion.

containing a 4. A light-sensitive hydrophilic colloid-silver halideemulsion containing 1-hydroxy-4-phthalimido-N-[6-(2,4- di-t-amylphenoxy)butyl] -2-naphhamide.

5. A light-sensitive hydrophilic colloid-silver halide emulsioncontaining l-hydroxy-4-(dodecenylsuccinimido)-N-[5-(2,4-di-t-a-mylphenoxy)butyl]-2-naphthamide.

6. A light-sensitive hydrophilic colloid-silver halide emulsioncontaining 1 hydroxy-4 (1,2-cyc1ohexyldiearboximido) N [5(2,4-di-t-amylphenoxy)butyl] 2- naphthamide.

7. In a multilayer multicolor element containing incorporatedcolor-forming couplers, the improvement comprising the incorporation ofa two-equivalent coupler which is capable of forming a dye on couplingwith the oxidation product of an aromatic amino developing agent, saidcoupler containing at least one 4-hydroxy-1-naphthyl group wherein thehydrogen atom of the 1-position of said naphthyl group has been replacedwith an imido group.

8. In a multilayer multicolor element containing incorporated colorformers, the improvement comprising the incorporation of a coupler ofthe formula:

CON

wherein R and R each represent a group selected from the classconsisting of the hydrogen atom, an alkyl radical, an aryl radical, aheterocyclic radical having 5 to 6 members in the ring, and, together,the nonmetallic atoms necessary to complete with the nitrogen atombetween them a nitrogen containing heterocyclic ring having from 5 to 6members in the ring; R R R and R each represent a group selected fromthe class consisting of the hydrogen atom, an alkyl radical, an alkoxyradical, an aryl radical, an aryloxy radical, R and R taken togetherform a valence bond between the two carbon atoms, and R R R and R takentogether provide the atoms necessary to complete a ring selected fromthe class consisting of isocyclic and heterocyclic, and R represents agroup selected from the class consisting of hydrogen, lower alkyl, loweralkoxy, and a lower amido group.

9. In an image-forming layer, the improvement comprising the use of acoupler which is capable of forming a dye on coupling with the oxidationproduct of an aromatic amino developing agent, said coupler containingat least one 4-hydroxy-1-naphthyl group wherein the hydrogen atom of the1-position of said naphthyl group has been replaced with an imido group.

10'. In an image-forming layer, the improvement comprising the use of acoupler of the formula:

wherein R and R each represent a group selected from the classconsisting of the hydrogen atom, an alkyl' radical, an aryl radical, ahetetocyclic radical having 5 to 6 members in the ring, and, together,the nonmetallic atoms necessary to complete with the nitrogen atombetween them a nitrogen containing heterocyclic ring having from 5 to 6members in the ring; R R R and R each represent a group selected fromthe class consisting of the hydrogen atom, an alkyl radical, an alkoxyradical, an aryl radical, an aryloxy radical, R and R taken togetherform a valence bond between the two carbon atoms, and R R R and R takentogether provide the atoms necessary to complete a ring selected fromthe class consisting of isocyclic and heterocyclic, and R represents agroup selected from the class consisting of hydrogen, lower alkyl, loweralkoxy, and a lower amido group.

11. A process for forming a cyan dye image in an image-forming layercomprising the step of contacting the said layer with an aqueousdeveloper solution comprising an alkali and a primary aromatic aminodeveloping agent in the presence of a coupler which is capable offorming a cyan dye on coupling with the oxidation product of an aromaticamino developing agent, said coupler containing at least one4-hydroxy-1-naphthyl group References Cited UNITED STATES PATENTS3,005,709 10/1961 Coles 9655 3,253,924 5/1966 Loria et al. 96-1003,311,476 3/1967 Loria 96--l00 NORMAN G. TORCHIN, Primary ExaminerALFONSO T. SURO PICO, Assistant Examiner US. Cl. X.R. 9655

